Platelet transfusions are currently the only effective treatment for severe thrombocytopeniaSevere thrombocytopenia A dangerously low platelet count, typically below 50,000 platelets per microliter and sometimes far lower in FNAIT. and can be lifesaving for dangerously ill fetuses and newborns.
Intrauterine platelet transfusions may be considered in severe cases during pregnancy, and intravenous platelet transfusions are used systematically in suspected cases of fetal and neonatal alloimmune thrombocytopenia (FNAITFetal and neonatal alloimmune thrombocytopenia A rare condition in which a mother’s immune system attacks fetal platelets, leading to dangerously low platelet levels before and/or after birth.) in newborns.
What is FNAIT?
Fetal and neonatal alloimmune thrombocytopenia (FNAIT) is a rare but serious condition that affects 0.1% of pregnancies in which a pregnant mother’s immune system produces antibodies against the platelets of her fetus. This occurs when a fetus inherits platelet antigens from the father that are not compatible with the mother, typically involving a protein called human platelet antigen (HPA). The mother’s immune system recognizes the fetal platelets as foreign, attacking and destroying them, leading to low platelet levels (thrombocytopenia) in the fetus or newborn.
Intrauterine platelet transfusions in FNAIT-affected pregnancies
Intrauterine platelet transfusions were formerly considered standard care in pregnancies affected by FNAIT. They can boost platelet levels and prevent severe thrombocytopenia.
However, their use involves a high risk of complications such as fetal distress often related to fetal bradycardia, premature labor, infection and miscarriage. The risk of uncontrolled bleeding leading to hemorrhageFetal hemorrhage Any bleeding that occurs before birth. In FNAIT, this usually results from extremely low platelet counts. as a result of this invasive procedure is also high, as a low fetal platelet countPlatelet count A measure of how many platelets are in the blood. FNAIT is characterized by severely reduced counts in a fetus or newborn. impairs blood clotting.
In recent years, the use of intravenous immunoglobulin (IVIG) with or without corticosteroids has become more common as an alternative to intrauterine platelet transfusions. This less invasive approach helps prevent severe fetal thrombocytopeniaThrombocytopenia A platelet count that is lower than normal. and avoid the risk of potentially life-threatening complications such as intracranial hemorrhageBrain bleed Bleeding inside the fetal brain, also known as an intracranial hemorrhage. In FNAIT, it's often caused by severe thrombocytopenia and can lead to long-term disability or death. (ICH).
Intrauterine platelet transfusions may still be considered in severe cases of FNAIT or if IVIGIntravenous immunoglobulin A treatment given to pregnant women with a history of FNAIT or known alloantibodies. IVIG reduces the immune reaction against fetal platelets. is not available. While there are risks involved, it may be the best option when the fetus has dangerously low platelet levels and ultrasounds show evidence of bleeding.
Intravenous platelet transfusions in newborns with FNAIT
Newborns suspected of FNAIT will receive urgent intravenous platelet transfusions to replace platelets destroyed by maternal antibodies during pregnancy. A diagnosis of FNAIT will be confirmed later, but symptoms such as a low platelet count, uncontrolled bleeding, bruising, petechiae and purpura, poor feeding and fussiness are indicative of thrombocytopenia and require urgent treatment.
Platelet transfusions can increase platelet counts and prevent the development of ICH, which can cause long-term neurological damage. Without urgent platelet transfusions, an infant can deteriorate quickly.
Risks of platelet transfusions in newborns are generally mild and may include a low grade fever, skin irritations and flushing. More serious side effects such as a drop in blood pressure, difficulty breathing and anaphylaxis have also been reported, but are rare.
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